Switching OpenGLContext's is an expensive hobby and implies a glFlush (I think) -which tends to show the partial construction of what we're rendering before its ready (ie. creates flicker). Currently we tend to re-use the OGL context that was previously associated with a VirtualDevice's SalGraphics; however since we un-bind our framebuffers from that each time we clearCurrent - then if we have a new context - we shouldn't try to restore the old context if we have another in-place, but instead just jump on the new context.
Michael Meeks committed a patch related to this issue. It has been pushed to "master": http://cgit.freedesktop.org/libreoffice/core/commit/?id=dd0fa60f6c289d7f290577cc240deb7b6e83fc8f tdf#94252 - avoid switching contexts un-necessarily to reduce flicker. It will be available in 5.1.0. The patch should be included in the daily builds available at http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: http://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.
Fixed in master; back-porting to 5.0.x in progress.
Michael Meeks committed a patch related to this issue. It has been pushed to "libreoffice-5-0": http://cgit.freedesktop.org/libreoffice/core/commit/?id=3891bd40f6cf513a020ac6c87acfd0af7fc5ffd8&h=libreoffice-5-0 tdf#94252 - avoid switching contexts un-necessarily to reduce flicker. It will be available in 5.0.3. The patch should be included in the daily builds available at http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: http://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.
Michael Meeks committed a patch related to this issue. It has been pushed to "libreoffice-5-0-2": http://cgit.freedesktop.org/libreoffice/core/commit/?id=9617d1c6a299901b79618d657e31635e59eda007&h=libreoffice-5-0-2 tdf#94252 - avoid switching contexts un-necessarily to reduce flicker. It will be available in 5.0.2. The patch should be included in the daily builds available at http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: http://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.